One of Makoto's work colleagues. Not married. Has many fantasies about women and often says vulgar things making Makoto blush. Okahama himself thought he was good at sex until girl colleagues started to discuss the types of men they hated most. Then it revealed that he had a lot of problems, f.e. thought only about himself.
Makoto's father. A 52-year-old company officer. He is overly sensitive about his sex life, and far too protective of his youngest child, Jun. (source: http://en.wikipedia.org/wiki/Futari_Ecchi)
Makoto's elder brother. A 29-year-old lawyer. He is very nosy and frequently pesters Makoto about his sex life and fancies himself as Makoto's tutor on the topic of pleasuring women. In order to appease his own sex drive, he frequently visits brothels. Is used to speak in an extremely loud voice which (along with the topic Akira usually covers) makes everyone embarrassed.
Daitetsu, or Mr. Kunikida, is the Chief Director of the TAC. When Kaede and Momiji were born, Mr. Kunikida raised Kaede like his own daughter, but he exploited her ability to track down and kill the Aragami. However, when Kaede sacrificed herself, he felt heartbroken. With Momiji in the TAC, Mr. Kunikida decides not to exploit her abilities like he did with Kaede and instead treated her like a normal girl. Source: Wikipedia
Orphaned at the age of ten because her parents were killed by the Blue, Marlene was one of the few lucky ones to make it to Second Earth. Since then Marlene has dedicated and trained herself to defeat the Blue, taking all kind of vicious training during her early days making her lack of many female atitudes. She doesn't understand the difference between a woman and a man, making it difficult for Yuji to deal with her. Though seeming very cold in the earlier episodes, as time progresses, Yuji opens up Marlene's emotions.
A high-ranking member of the science division on Second Earth. He suggests that Marlene and Yuji are kept together in order to get the best results from Yuji in the sleeper program. Not agreeing with the High Council's leadership of Second Earth or it's reckless use of the sleepers, he eventually forms a group called The Arc.